THE HEREDITY OF RICHARD ROE. 131 



mathematics easier had his father devoted his life to 

 exercise of that kind. But we are not sure that this is 

 so. W T e do not know yet on what terms X and Y and 

 X' and Y' are passed over to Richard Roe, or whether 

 they are passed on to him at all. In the view of Her- 

 bert Spencer (" Neo-Lamarckism ") X and Y are inher- 

 ited, just as A and B are. According to Weismann and 

 his followers they are not subjects of heredity at all. 



I can not pretend to say what will be the final de- 

 cision of science in regard to this vexed question. I 

 venture, to suggest that in Lamarck's law and in the 

 theories of many of his modern followers, too high value 



X Y 



has been set, not on X and Y, but on and . On the 



other hand, if these fractions are really equal to zero, if 

 acquired characters are absolutely of no value in hered- 

 ity, some problems in biology we have thought easy 

 become tremendously complicated. We must rewrite a 

 large portion of the literature of sociology. We must 

 give a new diagnosis to Ibsen's Ghosts. We must, in 

 fact, do this in any event, for inheritance such as the 

 Norwegian dramatist pictures it, belongs not to heredity 

 at all, but is to be sought for among the phenomena of 

 transmission and nutrition. They are matters of vege- 

 tative development rather than of true heredity. Of 

 the same nature is probably the recurrence of " spent 

 passions and vanished sins " that certain psychologists 

 ascribe to heredity. 



We may, I think, set aside the inheritance of ac- 

 quired characters as not being a large factor in the 

 changes of. the higher animals. Prop- 

 a u . re c erly speaking, as Mr. Archdall Reid has 



characters we ^ snown > nearly all the characters of 



the adult are "acquired characters" as 

 distinguished from innate characters. Heredity, for ex- 



